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(No Model) 0. J. FRAVEGA & A. JANET.

4 Sheets-Sheet 1.

FLEXIBLE SHAFT FOR DRIVING MECHANISM.

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Patented July 2, 1895.

in ventorx 1m Model.) 4-Sheets--Sheet 2 0. J. PRAVEGA & A. JANET.PLBXIBLBSHAFT FOR DRIVING MECHANISM.

No. 541,997. Patented July 2, 1895,.

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(No Mo'deL') I 4 Sheets-Sheet 3.

G. J. FRAVBGA 8: A. JANET. FLEXIBLE SHAFT FOR DRIVING MECHANISM.

No.541,997. PatentdJuly 2,1895.

(No Model.) 4 Sheets -Sheet. 4.

C. J. FRAVEG'A'8Z; JANET. FLEXIBLE SHAFT FOR DRIVING MECHANISM.

No. 541,997. Patented July 2, 1895.,

FIG-.13

UNITED STATES PATENT OFFICE.

CHARLES J. FRAVEGA AND ARMAND JANET, OF TOULON, FRANCE.

FLEXIBLE SHAFT FOR DRIVING MECHANISMS.

SPECIFICATION forming part of Letters Patent No. 541,997, dated July 2,1895. Application filed July 28, 1894:. Serial ll'o. 5l8,793| (N0model.) Patented in France March 20, 1894, No. 237,076-

To all whom it may concern:

Be it known that we, CHARLES J ULES FRA- VEGA and ARMAND J ANET,citizens of France, and residents of Toulon, in the Department of theVar, France, have invented a new and useful Improvement in FlexibleShafts for Driving Mechanisms, (which has been patented in France byPatent No. 237,075, dated March 20, 1894,) of which the following is aspecification.

This invention relates to flexible shafts serving for the transmissionof rotary motion produced by an engine (stationed permanently ortemporarily at a predetermined place) to mechanism, whatever itssituation or direction of motion.

The flexible shafts hitherto used have consisted of suitably arrangedmetal spirals, while the main part of the improved flexible shaftconstituting the present invention is a chain the operation of which asa flexible shaft is based upon the principle that if a twisting orrotary movement be imparted to one end of a chain the other end willtend to follow the direction of this movement, and the chain mayconsequently be utilized as a means of transmission of rotary motionprovided it be prevented from forming loops or knots by winding aboutitself. This end is attained, according to the present invention, byeither employing a suitably-fitted chain or by adding to an ordinarychain various parts or attachments, such as are hereinafter described,so as to make it fit for'use as a flexible shaft.

In the former case the flexible drivingshaft constructed according tothis invention is characterized by the following peculiarity: Thesuccessive links of the chain may be of a shape which may vary accordingto circumstances, but which should be such that, when these consecutivelinks are fixed or jointed together, their hinge-pins are arrangedalternately at right angles to each other. The shape of the links issuch that they present abutting or contact surfaces to each other, whichsurfaces meet at predetermined times, so as to limit the amplitude ofthe angle between adjacent links. By such means the flexible shaft orchain can assume the general outline of a double curve without becominglooped or wound about itself, though the radius of the curve should atno point thereof exceed the minimum compatible with the proper operationof the driving-shaft in prac tice.

The invention will be best understood by reference to the accompanyingdrawings, in which- Figures 1 to t represent one form of flexibledriving shaft or chain constructed according to our invention and havingcylindrical links, the figures being respectively elevations at rightangles to each other and two perspective views, also at right angles toeach other. Figs. 5 to 8 are similar views representing a modified formof the link shown in the preceding figures. This form of link shall beherein referred to as a prismatic link. Fig. 9 isa front view of alength of chain consisting of four links constructed according to thisinvention, the two extreme ones of which have reached their limit ofinclination or their extreme angular position in relation to the twocentral links, which form between them an intermediate angle; Fig. 10 isa top view of the same segment. Figs. 11 to 14 are respectivelylongitudinal elevations at right angles to each other and twoperspective views, also at right angles to each other, showing asimplified form of link more especially intended for shafts which haveno considerable strains to transmit.

Like reference numbers and letters designate like parts in all figures.

The link shown in Figs. 1 to 4; may be taken .to be formed from asection or length of a bar supposed to have been originally of circularshape in section, but cut or hammered down so as to present in twoplanes at right angles to each other a tongue forming the male part ofthe hinge 2 and perforated at one end as at 3, while at the other end ofthe link there is the corresponding groove or female part of the hingeformed by two checks 4 4:, having perforations 5 5, coinciding in such amanner that one of them forms a continuation of the other.

The male portion of one of the links engages in the female portion ofthe next link and the joint is completed by a hinge pin or bolt rivetedor otherwise secured at its two ends or retained in place by othersuitable means, so that when the chain is fitted toinc ' an ordinaryflexible shaft.

gether its consecutive links can turn about their axes, such as a: a:and y y, alternately at right angles to each other.

As shown in the drawings, the tongue 2 and each of the cheeks 4 4terminate in plane inclines 7 8 and 7 9, symmetrical in relation to thetwo diametrically-opposite planes of the link. When the angle ofinclination, either at one or the other side of any one link in relationto the next link attains certain predetermined proportions, therespective edges 8 and 9 of the tongue of the male part 2 and those ofthe checks 4 4 of the female part of the hinge meet, respectively, thebottom 10 of the groove between the two cheeks and the two planesurfaces 11 and 12, contiguous to the tongue 2. hen this position isreached, the angle of inclination cannot be further increased, and theconsecutive links are thus prevented from forming too large an anglebetween them, as an unduly enlarged angle would interfere withthe'proper operation of the flexible shaft in practice and bedetrimental to the useful effect of the transmission. The chains orflexible shafts of this description, owing to the cylindrical shape ofthe links, may be advantageously surrounded with a tubular case orsheath made of a suitable fabric or flexible or elastic material, suchas india-rubber, for example, capable of protecting them from dust andof deadening any shocks which they may sustain, while imparting to thewhole the outward appearance of hen it is preferred to dispense withthis casing, the chain may consist of prismatic links, such as are shownin Figs. 5 to 10. These links are constructed and arranged to operate inthe same manner as the links hereinbefore described; but instead ofbeing formed from a cylindrical bar or rod they may be formed from aprismatic bar of square or rectangular shape in section. A chain thusformed of links connected together by bolts 6 6 will presenttheappearance shown in Figs. 9 and 10, which figures clearly illustratethe manner in which in this form of chain the angle of inclination ofone link to the other is limited.

It will be seen that in both the forms of links above described thebolts 6 only serve to prevent the links from becoming disconnected fromeach other, without, however, subjecting them to any strain inconsequence of the twist imparted to the chain,inasmuch as each of thetongues or male parts of the hinge is snugly fitted between thetwocheeks constituting the female portion of the hinge, which sustainany strain that may be produced by twisting the chain. This is animportant advantage, insuring great durability to the chain, for whilethe mutual pressure exercised by the respective contact-surfaces ofadjacent links is distributed over a comparatively large surface thebolts, on the other hand, are subjected to a very slight strain, and thewear both of these bolts and of the links themselves is reduced to aminimum. These facts are sufficiently important to outweigh anyconsideration of cost in those cases where the object in view is toprocure a durable device and to transmit considerable power. Vhere,however, the flexible shaft is intended to transmit but small power, itmay be sufficient to employ a chain formed of links constructed in themanner illustrated in Figs. 11 to 14, the arrangement being in that caseconsiderably simplified. These links, like those shown in Figs. 5 to 10,have a prismatic body, but include no female portion. They are joinedtogether by means of bolts or pins traversing the projections 2, thethickness of each of which is equal to one-half of the body of a link,the angle of inclination of every two consecutive links being limited inthe same manner as in the preceding forms of links.

It will be readily seen that the construction of these links isextremely simple and cheap; but the bolts 6 in this case have to resistthe strain resulting from the tendency of the contact-surfaces of thelinks to move away from each other, and they are also more subject towear. Where it is desired to surround this chain with a protecting case,these links, like those shown in Figs. 1 to 4, may be constructed with acylindrical body fitting the shape of the case more exactly. To avoidcomplication, this last type of cylindrical link has not been shown inthe drawings, but it will be readily understood from the description ofthe last form of link.

We wish it to he distinctly understood that we do not limit ourselves tothe few forms here represented only to facilitate the perusal of thedescription of our invention, and that modifications can be made,according to circumstances, in the shapes, dimensions, proportions, andmaterial employed in the construction of the improved flexibledrivingshaft so long as the substance of our new invention or improvement is employed.

We claim ICO IIO

' A flexible power-transmitting shaft composed of links hinged togetherwith the hinge axes at different angles and said links provided withabutting or contact surfaces within the angles of flexure of said shaft,whereby the shaft has the degrees of flexure limited at the severalhinges by the chain itself unre-- strained by outside means such asnon-rotating casings, substantially as described.

In testimony whereof we have signed this specification in the presenceof two subscribing witnesses.

C. J. FRAVEGA.

